The objectives of the proposed program are to develop and otherwise obtain, characterize, expand, bank and distribute cell lines of use for studies on cancer of the large bowel. Developmental efforts will require use of normal intestinal tissue from humans and laboratory animals. Definition of most suitable dissociation and culture methods will include trials with standard reagents as well as with novel published techniques. Fractionation attempts will include centrifugation using isopycnic and isokinetic gradients of bovine serum albumin of ficoll. Biochemical, histochemical histoenzymological and ultrastructural markers will be used to monitor success. Specific cell types will be followed from the intact tissue, through dissociation and fractionation then primary mass and clonal culture. Cultivation of fractionated epithelia as colonial aggregates, and co-cultivation schemes with mesenchymal elements are outlined. Banking of lines developed at the ATCC or submitted from the field will be accomplished using described methods in consultation with an advisory committee. The latter will be established specifically for this facility and will consist of recognized experts in gastroenterological research. Required expertise in all areas of microbiology will be contributed from each department at the ATCC. Certified cellular material made available through this resource would be uniform and available throuth perpetuity thus ensuring research comparability over the long term. The contribution to our understanding and control of the large bowel should be significant.